Space Based Solar Power (SBSP) was initially brought up when looking into how to bring non-aeropsace companies into the industry.

The major souce of information is the NSSO report published in 2007:

http://www.nss.org/settlement/ssp/library/final-sbsp-interim-assessment-release-01.pdf

An interesting article about it from NSS:

http://www.nss.org/adastra/AdAstra-SBSP-2008.pdf

Here's a very rough initial write-up about SPSB. The source of information is the NSSO report.

Initial Write-Up for SBSP

John Springmann

Space-based solar power (SBSP) is a great way to engage and encourage non-aerospace companies in the commercial development of space. Space-based solar power consists of large solar panels in Earth-orbit that transmit energy to Earth-based receiving stations via microwaves. Recent studies show that SBSP is technically feasible with current technologies.

There are many reasons why SPSP should be developed. SBSP is a clean, reliable, and plentiful source of energy. Solar arrays based in North America can generate 125-375 W/m² of power, but 1366 W/m² of energy could be captured by space-based solar arrays. SBSP directly supports the goals of the US National Space Policy and Vision for Space Exploration which seeks to promote international and commercial participation in space. SBSP is a clean alternative to finite amounts of fossil fuels and is an alternative to nuclear power, decreasing hazardous nuclear waste. SBSP will increase international cooperation, and SBSP would enable a true space fairing civilization.

Essentially, the only factor preventing development is high launch costs and the lack of easy access to space. According to the SBSP Phase 0 Architecture Feasibility Study by the National Security Space Office (NSSO), construction of a single SBSP satellite would require at least 120 launches. In general, launch costs are the only major factor limiting the development and use of space, and SBSP will encourage companies to develop technology to decrease the costs.  SBSP will catalyze the development of commercial access to space, and in the same way, development of commercial access to space will catalyze the development of SBSP.

The first step in developing SBSP is a demonstration.  A prize should be offered for the first demonstration of power beaming from one satellite to another. This will be followed by power beaming from a satellite to Earth. Since it was first proposed in the 1960, approximately $80 million has been spent in the study of SPSP. In contrast, since the 1950s, approximately $21 billion has been spent for the development of fusion power. Initial government funding could come from this fusion budget, since SBSP harnesses existing fusion – the sun. SBSP is a potentially enormous market, and after a successful demonstration, existing energy companies as well as new companies will invest to get their share of the market. The Department of Defense (DoD) has stated that it does not want to develop SBSP, but rather buy it at a fixed cost. Therefore, DoD would be the anchor customer for SBSP with potential additional costumers including large energy companies and NASA.

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Final SBSP write-up from RSFC:

The focus will now shift to a look at suggestions to increase business opportunities for commercial space, and this section focuses on the energy market. Energy is a necessity in everyday life, and the demand for energy is constantly increasing. Energy is one of the most important and valuable resources on the planet. Energy markets are well known to investors and have the potential to attract many non-aerospace companies.

Space based solar power (SBSP) is a way to generate electricity in space for use on Earth. SBSP consists of large solar panel arrays in Earth-orbit that collect energy directly from the sun and transmit it to Earth-based receiving stations wirelessly. Recent studies show that SBSP is technically feasible with current technologies.

SBSP should be developed for many reasons. SBSP is a clean, reliable, and plentiful source of energy. Solar arrays based in North America can generate 125-375 W/m2 of power, but 1366 W/m2 of energy could be captured by space based solar arrays (40). SBSP directly supports the goals of the US National Space Policy and Vision for Space Exploration, which seeks to promote international and commercial participation in space. SBSP is a clean alternative to both finite fossil fuels and nuclear power, which produces hazardous nuclear waste. SBSP has the potential to increase international cooperation and enable a true space faring civilization.

There are two main components of SBSP. The first is the conversion of solar energy into power, and the second is transmitting this power to Earth wirelessly. Solar panels are a technology that is continuing to improve. Solar panels have demonstrated 28% efficiencies at room temperature, and projections estimate efficiencies of 50% reached within the next two decades (41). Wireless power beaming has also been demonstrated in the past. For example, 30 kW of power was beamed over 1 mile by JPL in 1975 (42). NASA is also currently offering a prize challenge for power beaming technology demonstration. Details on this prize can be found in Appendix C.11.

The major obstacle to developing and improving SBSP is a lack of organization and funding. Since the National Security Space Office (NSSO) SBSP study came out in fall 2007, no funded work has been completed. The first step is to determine who should be in charge of coordinating the development. Although SBSP clearly involves space, it is mainly an energy technology, and therefore should be managed by someone such as the DOE. An organization within or directed by DOE, such as Energy Research and Development Organization (ERDO), which preceded DOE and no longer exists, should take responsibility.

At this point in development, a relatively small amount of funding is necessary. We propose funding on the scale of $10 million, and it can easily be justified to congress as a small investment into new technology that will help us attain energy independence. A small amount of successful funded research should grow exponentially when the technology potential is seen and pursued by industry and universities. Since it was first proposed in the 1960s, approximately $80 million has been spent in the study of SBSP. In contrast, since the 1950s, approximately $21 billion has been spent for the development of fusion power (40). Government funding for SBSP should be increased to a comparable level.

The other major factor preventing SBSP development is high launch costs and the lack of easy access to space. According to the SBSP Phase 0 Architecture Feasibility Study by (NSSO), construction of a single SBSP satellite would require at least 120 launches. In general, launch costs are the only major factor limiting the development and use of space, and SBSP will encourage companies to develop technology to decrease these costs. SBSP will catalyze the development of commercial access to space, and in the same way, development of commercial access to space will catalyze the use of SBSP.

It is impossible to put a price tag on SBSP because the technologies involved still need to be developed and demonstrated. For example, the current specific power of solar arrays is 180 W/kg, but is expected to improve to 1000 W/kg over the next two decades (41). Technologies such as this should be able to be applied to many things other than SBSP along the way, and that should offset the cost of development. Once SBSP is actually deployed in space and customers purchase its electric power, it will pay for itself.